HEALTH ENCYCLOPEDIA

Allergic Urticaria

Overview

Allergic urticaria, also called acute urticaria, is a skin condition that causes hives and itching due to emotional stress or allergic reactions from foods, medications, and/or various environmental factors. These hives normally last for only a few minutes, but sometimes can last for several days. According to experts at the American College of Allergy, Asthma, and Immunology, acute urticaria affects up to 20 percent of the population at some point in their lives.

What Are the Cause of Allergic Urticaria?

Allergic urticaria is often the result of coming in contact with allergens. These allergens include, but are not limited to:

animal dander

shellfish, nuts, fish, milk, eggs, or other type of food

pollen

insect bites

medications

Other conditions that can make allergic urticaria worsen are:

stress

extreme changes in weather (extreme heat and cold)

autoimmune diseases, such as thyroid disease or lupus

What Are the Symptoms of Allergic Urticaria?

The most significant feature of allergic urticaria is the outbreak of a skin rash. This rash may appear as red, swollen, and inflamed welts, bumps, or patches. As the rash gets bigger, it forms hives, which are large flat red areas that protrude above the skin’s surface. Since allergic urticaria arises when you come in contact with a known allergen, you may experience additional symptoms, such as a mild fever, coughing, and runny nose. However, if you experience any of the following contact a medical professional immediately:

trouble breathing

swelling in the mouth or eyes

swelling in the throat

dizziness

severe hives

hives that persist beyond a few days

How is Allergic Urticaria Diagnosed?

The signs and symptoms of allergic urticaria may be obvious upon inspection. However, your physician will ask questions about your medical history to help pinpoint a primary cause. If you have a known history of allergens, share this information with your physician. If the cause is not immediately clear, or if an additional cause is suspected, he or she will order a skin allergen test or blood test to confirm a diagnosis. A skin test is often performed by applying an extract of an allergen to your skin, scratching or pricking the skin to allow exposure, and then evaluating the skin’s reaction. It may also be done by injecting the allergen under the skin, or by applying it to a patch, which is worn on the skin for a specified period of time. Allergy blood tests look for substances in the blood called antibodies. Blood tests are not as sensitive as skin tests, but are often used for people unable to have skin tests.

How is Allergic Urticaria Treated?

As much as they may itch, avoid scratching your hives. This makes them spread further and it may break the skin’s surface, which makes you susceptible to skin infections.

In most cases, allergic urticaria symptoms disappear without treatment. However, if the itching and swelling become problematic, use an over-the-counter anti-itch cream, lotion, or powder that contains at least 1 percent hydrocortisone. If your doctor feels your urticaria is related to seasonal allergies he or she may suggest over-the-counter antihistamines such as:

Claritin

Allegra

Zyrtec

Xyzal

Clarinex

Benadryl (Benadryl causes drowsiness, so it’s best to use this medication before bedtime.)

How is Allergic Urticaria Prevented?

The most effective way to prevent allergic urticaria is to avoid contact with the known allergen. An allergist may determine what allergen triggers your urticaria. Keeping a diary of what foods you eat and any reactions you experience can help your allergist pinpoint possible culprits. If you take any prescription medication and notice an outbreak of hives or a rash, notify your physician immediately.

What is the Long-Term Prognosis?

In more serious cases of allergic urticarial, swelling of the mouth and throat may occur. These are symptoms of anaphylactic shock and could become life threatening. They occur rapidly and warrant immediate medical care. If you are treated for this condition, and the cause is determined, your physician will prescribe a medication for you to carry at all times to prevent symptoms or to stop them once they develop.

Content licensed from:

Written by: April Khan and Matthew SolanMedically reviewed
: George Krucik, MD

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.